Staining apparatuses for staining and treating samples by means of probes normally comprise a first station for containing one or more reagent vials; a second station for mounting slides, a probe arranged to aspirate a portion of reagent from a selected reagent vial and dispensing the reagent to a slide on which the sample is arranged and a drive means for moving the probe between the various stations.
A sample is in this application to be understood as a biological sample such as histological samples, e.g. tissue and cell specimens, including cell lines, proteins and synthetic peptides, tissues, cell preparations, blood, bodily fluids, bone marrow, cytology specimens, blood smears, thin-layer preparations, and micro arrays, and specifically biological samples on microscope slides.
The term staining is used for the end product of the process, by which certain parts of the sample may be stained, i.e. have obtained a different colour, either in the optic range or in another electromagnetic range, such as ultra violet, or the staining may be a detectable, preferably an automatically detectable, change in properties, such as fluorescent properties, magnetic properties, electrical properties or radioactive properties. To obtain the staining, the sample normally has to undergo a series of treatment steps, such as, but not limited to; washing, binding of reagents to the specific parts of the sample, activation of the reagents, etc. and each treatment step may include a plurality of individual treatments.
The vial station is a collection of a plurality of vials, at least two but often 20-60 vials or more, which may or may not be physically arranged in close proximity to each other. The term station does not indicate that the vials must be located within one, confined area; rather it indicates the existence of a plurality of vials. The probe drive means may be a robot arm with two or three degrees of freedom, such as an articulated arm or one track or a set of perpendicular tracks along which a probe retainer of the probe drive means may be displaced, wherein the probe retainer may be moved in a direction normal to the track or tracks. The skilled person may readily design other types of probe drive means, e.g. combinations of the above described. The carrier means may be provided to the apparatus in a two-dimensional array, e.g. constituted by individual rows of carrier means as discussed in the example below, or the carrier means may be provided in any manner known in the art, e.g. arranged in a carrousel or as a row of carrier means. The carrier means may also be arranged movably with respect to the probe drive means, such as in an endless row that is advanced automatically past the operating area of the probe drive means or as a two-dimensional array that may be moved in a direction perpendicular to a travel direction of the probe drive means, so that the probe may reach any carrier means by the combined movement of the probe and the array.
The carrier means are preferably arranged in groups or series on trays or the like, so that a plurality of carrier means may be removed from or situated in the apparatus simultaneously, and the apparatus preferably also comprises means for performing the intermediate storage of the carrier means with samples thereon and the removal of the carrier means from the apparatus automatically.
The operation of the staining apparatus will generally be controlled by means of control means, typically a computer having a central processing unit and one or more memory unit associated therewith, means for controlling the various operations of the apparatus by controlling step motors, solenoids, valves and/or other drive or control parts of the apparatus. The control means may have one or more data communication ports for enabling data communication with external computers by wire or wireless. The control means does not have to be physically arranged within the apparatus itself but may be a computer external to the staining apparatus and connected to the apparatus via a data transmission port thereof.
Applications to which the present invention may especially relate include immunohistochemistry, in-situ hybridization, fluorescent in-situ hybridization, special staining, and cytology, as well as potentially other chemical and biological applications.
Sample processing in immunohistochemical (IHC) applications and in other chemical and biological analyses may require one or a number of various processing sequences or protocols as part of an analysis of one or more samples. The sample processing sequences or protocols may be defined by the individual or organization requesting an analysis, such as a pathologist or histologist of a hospital, and may be further defined by the dictates of a particular analysis to be performed.
In preparation for sample analysis, a biological sample may be acquired by known sample acquisition techniques and may comprise, for example in IHC applications, tissues generally or, even in some applications, one or a plurality of isolated cells, such as in microarray samples, and may be presented on a sample carrier such as a microscope slide. Furthermore, the sample may be presented on the carrier variously and potentially in some form of preservation. As one example, a sample such as a layer or slice of skin may be preserved in formaldehyde and presented on a carrier with one or more paraffin or other chemical layers infiltrating the sample.
Immunologic and histological applications, for example, may require processing sequences or protocols that comprise steps such as deparaffinization, target retrieval, and staining, especially for in-situ hybridization (ISH) techniques. Previously, in some applications, these steps may have been performed manually, potentially creating a time-intensive protocol and necessitating personnel to be actively involved in the sample processing. Attempts have been made to automate sample processing to address the need for expedient sample processing and a less manually burdensome operation. However, such previous efforts may have not fully addressed the needs for an automated sample processing system. Previous efforts to automate sample processing may be deficient in several aspects that prevent more robust automated sample processing, such as: the lack of sufficient computer control and monitoring of sample processing; the lack of information sharing for processing protocol and processing status, especially for individual samples; the lack of diagnostic capabilities; and the lack of real-time or adaptive capabilities for multiple sample batch processing.
Past efforts at automated sample processing for samples presented on carriers such as slides, such as U.S. Pat. No. 6,352,861 to Ventana Medical Systems, Inc. and U.S. Pat. No. 5,839,091 to LabVision Corporation, have not afforded the various advantages and other combinations of features as presented herein.
U.S. Pat. No. 5,948,359 discloses an apparatus of the above mentioned type, wherein the first station comprises a vial holder for holding 40 or more vials in order to provide a wide range of different reagents adapted for different staining purposes, and thereby the possibility of automatically staining a large number of slides requiring different staining processes. In practice, it is very important that the apparatus facilitates that many different staining processes can be performed at the same time in the apparatus, because this avoids the necessity of batching samples requiring the same procedure or other treatment with reagents, and processing each batch individually.
U.S. Pat. No. 5,839,091 discloses a staining apparatus and a method of the above-mentioned kind, said apparatus comprising a reagent probe assembly for applying reagents onto a slide and wherein the probe is washed between the individual reagent applications in a wash station.
U.S. Pat. No. 6,537,818 discloses a system and method of aspirating and dispensing reagent. Also US 2003/0194349; U.S. Pat. Nos. 6,498,037; 6,436,349; 5,213,764, 4,869,114; and U.S. Pat. No. 3,960,020 show probes dispensing reagents.
An object of the present invention is to provide a reagent delivery system for a sample processing apparatus and a probe assembly therefore wherein the accuracy of dispensed volumes and the throughput is better than hereto known. Further objects of the present invention are to improve upon the known apparatuses for staining samples as well as the method for automatic staining of samples by facilitating a wider range of available processes of treatment, so as to increase the number of different staining and/or treatment processes that may be performed automatically, alternatively or additionally to provide an increased quality of some specific staining processes.